DESCRIPTION (provided by candidate): The aim of the proposed work is to examine the hypotheses that prenatal choline supplementation enhances neurogenesis in adult and aged rats, and moderates stress reactivity in adult rats. Choline availability in utero modulates hippocampal cholinergic function and memory in adulthood, and prenatal choline supplementation, specifically, enhances hippocampal function and morphology, and has the extraordinary effect of preventing declines in memory in aged rats. Enhanced and preserved neurogenesis across the lifespan may be one mechanism by which prenatal choline supplementation confers a cognitive advantage to adult and aging rats. Stress reactivity is also established during development and is subject to modification by perinatal environmental factors. Altered HPA function may contribute to choline's positive effects in adulthood and choline may prevent stress' negative effects on aging. Findings consistent with this proposal would be the first to demonstrate that prenatal choline supplementation enhances neurogenesis in adulthood and has the capacity to moderate physiological, behavioral, and neuroanatomical responses to stress.